I am wiring my layout for cab control using Atlas Selector switched using this configuration: http://1.bp.blogspot.com/-g96D6zXj1IA/UVJhMhodOqI/AAAAAAAACMM/A3mo_V5xDKg/s1600/Dual-Cab-Control.jpg. I would like to put red and green lights for each block on my control panel to show whcih cab is running which block. Is that even possible with this configuration? Any help is appreciated.
Modeling the Pennsylvania Railroad in N Scale.
www.prr-nscale.blogspot.com
There is no really simple solution because internally the Selector is a series of center off, single pole, double pole, slide switches. Some suggestions:
1. Do without lights. Use the position of the block slide switch to determine which cab is powering the block. The top position is Cab A, the bottom position is Cab B, and the middle turns the block off. This is the default Atlas wiring. It does require that all Atlas Selectors receive Cab A power from the left top terminal, and Cab B power from the left bottom terminal. It also requires that there be enough ambient light and appropriate viewing angle to see the position of the slide switches.
2. Use the Atlas Selector output to drive a DPDT (can have more poles) relay. One relay contact will then determine whether Cab A or Cab B is selected. The second contact (pole) controls which light is illuminated. A relatively simple solution conceptually, but costs one relay per block. This solution also loses the center off position of the Selector, which can be pretty handy. The solution requires 2 cabs plus separate power for the relay and lights. The relay and lights can use the same power supply or separate.
3. Use DPDT (center off) toggle switches instead of Atlas Selectors for block controllers. Use one side of the toggle just like the Atlas Selector. The center terminal goes to the block, the upper to Cab A, and the lower to Cab B. The other side of the toggle switches the light power. The upper terminal goes to the Cab A light, the lower terminal to the Cab B light, and the center terminal to the light power supply. Advantage of this scheme is that the block toggles can be mounted directly in a layout diagram so that it is much easier to see what track a given toggle controls. Again, you can orient the toggles that handle pointing left (or up) always means Cab A selected, pointing right (or down) always means Cab B, and centered is block off. If you can see the toggle position, the lights become optional. Finally, you can scatter the individual block toggles around the layout instead of at a control panel, so that you can walk around the layout and control your train (you will want walk-around throttles for this). All the MR project layouts of the '60s and early '70s used block toggles instead of Atlas Selectors. Some had provision for walk-around control, some had a control panel, and some had both.
In either 2 or 3, the lights could be bulbs or LEDs. You simply power them according to their needs in a separate circuit.
my thoughts and experiences, your choices
Fred W